


an exercise in precision junk-flexing

by Laylah



Category: Homestuck
Genre: Come Inflation, Double Penetration, Established Relationship, Multi, PWP, Size Kink, Xeno
Language: English
Status: Completed
Published: 2014-05-13
Updated: 2014-05-13
Packaged: 2018-01-24 14:08:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,023
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1607927
Author URL: https://archiveofourown.org/users/Laylah/pseuds/Laylah
Summary: <blockquote class="userstuff">
              <p>"Whatever nasty ideas I just gave you, go for it. I'm your kinky alien sex toy for the night or whatever," and with Terezi looming over you and Karkat's big hands on you that's suddenly a seriously, intensely possible thing. You are having a vision of the future and it involves a <i>lot</i> of troll junk.</p>
            </blockquote>





	an exercise in precision junk-flexing

**Author's Note:**

  * For [Lizardlicks](https://archiveofourown.org/users/Lizardlicks/gifts).



> I was taking prompts for 500-word porn snippets and Licks said, "Dave/Terezi/Karkat. The trolls hit their adult molt getting ridic growth spurts and Dave finds out the hard way he has a size dif and stuffing kink."
> 
> I failed at 500 words but I sure succeeded at porn!

When you were fifteen you came to terms with the fact that Karkat was going to end up bigger than you. He went through his weird-ass subadult molt (seriously, what reasonable species does that) and came out the other side a big alien jarhead. Whatever, he's a tank, you can handle that. No threat to your death-dealing prowess at all.

But now Terezi's had _hers_ —she grows up slower, for bullshit alien biology reasons you refused to learn—and she's... She's not a tank. But she's not your pocket-sized collection of sharp edges anymore, either. She's like a seven-foot-tall sexy praying mantis climbing out of her cocoon and that comparison is _bad news_ in a way that gets a really unfortunate amount of your dick's attention.

Beside you Karkat is purring like he's about to rip some heads off.

Terezi turns her head toward the sound and shows you guys all of her freaky monster teeth, of which there are even more now than there were when she went into that thing. "Heh, did you wait up for me? That's sweet."

"Thought you might appreciate a little welcome back to the world of the living," you say. "Parade, twenty-one-gun salute, the works."

"Nookmunch," Karkat mutters.

"Or that," you say, mostly to annoy him.

"Bring him over here," Terezi croons.

By the time you realize she's talking to Karkat, he has you by the scruff and is hauling you bodily over there. You squawk at the affront to your dignity, but your Karkat-suplexing days are over, and you're not getting out of this unless you protest like you mean it. Which you don't.

You look up into Terezi's smiling face, and she leans down to breathe you in. She's lean and alien, naked and dripping with her cocoon goo, and Karkat's nails prick the sides of your neck where he hasn't let you go. You can see now how these assholes could be part of a species that chewed its way through the galaxy and spat out everything that challenged it. There's enough adrenaline in your veins for a platoon of skydivers. Your boner could level a small country.

"Fear smells good on you, coolkid," Terezi says.

"Wow, what," you say, "something happened to your sniffnozzle in there if you think what you're smelling right now is _fear_ ," and you can feel Karkat purring against your back, the way the noise changes gears just a second before Terezi stretches forward and kisses him over you. "Oh fuck."

Terezi starts to purr, too, and you can feel their different frequencies vibrating through your ribcage, meeting somewhere behind your sternum and shaking your foundations. We're reading an eight-point-one on the Richter scale, this is not a drill, duck and cover.

They're both pulling your shirt up.

"So what, is this some kinky thing where I'm the conduit passing sexy messages for you guys or something," you say, and Terezi stops for a second in the way that means you just got the attention of the prosecution.

"Complaining?" she asks. "Were you hoping to be our bucket instead?"

"Oh _god_ ," Karkat says, about as fervent and devout as you've ever heard anyone be.

"Whoa, I'm pretty sure that's nothing like acceptable hygiene practice, you could contaminate your alien baby batter with all kinds of weird shit, not to mention the physical improbability of, of, fuck," you whine as Karkat palms your cock through your pants.

Terezi tips her head down as if she's looking at you. "If you have an objection, you need to state it clearly."

You shake your head. "Let's not have the fucking safeword conversation again, okay? I'm cool. We're cool. Whatever nasty ideas I just gave you, go for it. I'm your kinky alien sex toy for the night or whatever," and with Terezi looming over you and Karkat's big hands on you that's suddenly a seriously, intensely possible thing. You are having a vision of the future and it involves a _lot_ of troll junk.

"Watch the cape," you say as they attack your clothes.

"Shut up, you insufferable bulgesore," Karkat says, and you're perfectly capable of translating that into the endearment it is.

Terezi's hands are long skittery spiders exploring your skin, which fails to be creepy mostly on the grounds that you have lost control of your life. You arch into her touch, let the two of them scatter your clothes all over the room, go along with it when Karkat pulls you down to the floor. You're eye-level with Terezi's bulge, so you lean forward and open your mouth. Her junk french kisses to put a lot of people's mouths to shame, teasing your tongue, flickering and retreating.

Which distracts you from Karkat until you feel his wet bulge exploring the crack of your ass. You shudder and squirm back against him, which is about as eloquent a _get on with it already_ as you can manage when your mutual girlfriend's alien dick has engaged you in championship tonsil hockey.

Getting Karkat's bulge up your ass post-molt is an exercise in precision junk-flexing, where he feeds it into you slowly and only swells up once he's deep enough in you that you can take it. Past you didn't think much about inflation as a kink, which shows how little attention that jerk paid to the timeline he was heading into, because now you're totally hooked: with each little ripple he gets bigger inside you, and you squirm and try to relax for more. The fullness and pressure make your dick ache, and you moan, leaning into Terezi to encourage her to fill you up too. Alien cockhound Dave Strider, that's you, doing your species proud.

When she pulls out of your mouth you might whine embarrassingly, and maybe you try to follow her just a tiny bit. But she doesn't go anywhere, just sinks down to her knees in front of you and smiles. "Think you can take more?" Her hand slides up the inside of your thigh, cups your balls, her fingertips stroking Karkat's bulge where it sinks into your ass.

"Oh my fuck," you say, "oh my fuck holy shit."

Karkat squeezes your hip with one meaty paw. "Keep breathing, asslord," he says. "Not happening unless you say you want it."

You lean back, bonk your head on his shoulder a little harder than you really need to. "Who do you think you're talking to? I am the grand fucking champion of intergalactic sex acrobatics, here. The alien fuck has not been invented that I can't handle."

Karkat bites your ear, and you yelp.

"I know too much sincerity makes you break out in hives," Terezi says, "but for the sake of Karkat's delicate nerves, can you at least try?"

"Oh, sure, pretend like I'm the one who gives a shit," Karkat says, rightfully breathless from the unparalleled pleasure of giving it to you up the ass. Terezi's hand moves between your legs and Karkat whines.

It drives you crazy that she always has to stop and check, that she makes you agree to all her terrible sexy ideas explicitly. You'd bet that's one of the reasons she does it.

Karkat has stopped pushing his way further into you, just holding still and trembling a little while Terezi does her thing—fingering his nook, probably, from the way his breath hitches against your ear. You squirm on his bulge in frustration. "Come on, Karkles, you're—letting me down, here."

He snarls the way he does when he's buying himself time to get all his expletives in order, and Terezi interrupts, "He's just being polite and not distracting you while you make up your mind. What do you think, coolkid? You want me up there too?"

Just as she finishes talking Karkat does give you one more throbbing pulse, because the troll version of good cop/bad cop is apparently hot cop/sexy cop and you are guilty of anything they want to put on your rap sheet right now. " _Yes_ ," you say, "yes, come on, I can't resist your wiles even when you're dripping with terrible cocoon goo, _do it_."

Terezi smiles like a shark that's trying to be sexy, and the awful thing is that it works. She leans forward and Karkat leans back, pulling you down on top of him, and you can feel how ridiculously much bigger than you he is, the way you don't even come close to covering his whole body. And then there's Terezi leaning over you, her hands on your thighs, pushing them up and out. You are so fucked, and that's still only half as fucked as you're going to be, any minute now.

"Breathe," Karkat growls, like you needed a reminder (maybe you needed a reminder). You breathe. Terezi's bulge strokes your balls, squirms down, nudges up against Karkat's. You breathe like a fucking champion.

"Take your own advice," Terezi says. Karkat's chest rises and falls under you, big deliberate motions. What's _he_ nervous about? Apart from the fact that he's had a hideous infatuation with Terezi basically since the first delicate stirrings of troll puberty round one, and sharing an asshole with somebody is pretty intimate contact, and oh god she starts pushing and you stop thinking about Karkat and just worry about breathing some more.

She's so careful, though, sneaking in the back door like a goddamn cat burglar, which is an entirely inappropriate metaphor for someone with the Pyrope justice fetish, but hey, if the bulge fits—and she's making it fit, holy fuck, you're going to have to revise your estimation of Terezi vs the law because she's got no regard at all for the laws of physics and honestly right now neither do you.

"Fuck, keep going, I'm fine," you gasp when she stops moving.

She licks your jaw. "Ssh, you can't rush these things."

"No, but Strider's right," Karkat says. "Don't fucking stop."

"Heh." She has the most ominous grin you have ever adored beyond reason. "Make me."

He growls like she's revving his engine or something and then you feel movement—his, you assume, because you're not a moron and you can read context, and also because her eyelids flutter like he just got her good. She catches her breath and there's more movement, slower, and he gasps.

They are _fucking your ass competitively_. That ought to be terrifying—okay, frankly it is terrifying—but it's also hot enough to melt steel, which is your excuse for how your spine feels right now. They shift and twist and swell inside you, these freaky motions that remind you with every twitch of your overstimulated nerves that you are stuffed to capacity with unreal amounts of alien dick.

Karkat gets one big meaty paw on your dick and you whine. You can barely stand it, all your signals crossing—you feel so full and heavy and swollen, wrecked right down to your foundations like some kind of hentai cliche. They don't thrust in and pull out, which (you imagine) would at least give you moments when you could catch your breath and remember what it felt like _not_ to be stuffed to within an inch of your life. Instead they just squirm and change shape, never letting you quite get used to how it feels, the pressure shifting constantly. You want to come and you're not sure if you can, when you don't have the room for your muscles to _do_ anything around the two of them splitting you in half.

"Fuck," Karkat is chanting, "fuck, fuck," and you're glad he's doing it so you don't have to.

"Like that?" Terezi asks, a little breathless, and it doesn't even matter that you're getting the universe's most halfassed handjob, this is still the hottest thing that's ever happened. To anyone.

Karkat's incoherent noise means he agrees.

Terezi licks your jawline, bites affectionately. "How about you, coolkid? How's your rocket's countdown sequence?"

"Oh my god, _never say that again_ ," Karkat demands as you stifle a laugh, which of course means you're going to ride that metaphor right into the ground.

You shake your head. "Mission Control, it looks like we're, nnhh, carrying t-too big a payload for liftoff."

Karkat's hand stops moving. "You oozing taintblister, Strider, you're supposed to _say_ something if we hurt you!"

You claw at his hip when it feels like he might be trying to withdraw. "Dude, chill your undersized purr jugs, I'm fine! You guys just have to go first this time because there is _literally no room_ for anything to clench down there which, in case you need it spelled out for you, is completely illegal levels of hot!" Somebody's bulge pulses, and you squirm down on them. "Come _on_ , don't stop."

It turns out they can, in fact, follow simple directions. Karkat stops trying to remind himself to jerk you off and Terezi leans over your shoulder to kiss him and you maybe kind of lose yourself in being so completely and utterly _done_ , filled with them and surrounded by them, breathing in the musky weird smell of aroused troll and enjoying it way more than biology would approve of. But fuck biology, basically. What did it ever do for you?

Nothing like this, you're pretty sure. Nothing like Terezi's lean angular body stretched out over you, or Karkat's dense heat under you, or the fucking unbelievable way they stuff you beyond full. Time slowing down is bullshit, and you know that better than anyone, but it still feels like these moments are stretching out just as much as you are, smearing your whole world into heat-pressure-want.

Terezi goes off first, her head thrown back and all her teeth bared, and suddenly you really are too full to stand it, with her come pumping into your ass when there wasn't any room left already. The sound you make doesn't do your dignity any favors and you're breaking out in a sweat, your skin flashing hot and cold. 

But Terezi's talking you through it, her voice a low cicada buzz and her hand on your side as the pressure eases until you can breathe again.

"You dumbfuck showoff," Karkat murmurs in your ear.

You turn your head and give him a glancing, awkward kiss. "I'm okay," you tell him, and your voice cracks, which makes you sound like an idiot but apparently the kind of idiot that makes Karkat's trouser snake slither, because he starts moving again, and not in the _whoops, better pull out before I break the human_ way.

And you did mean it, about being okay, more okay than you thought you were, even, as Karkat remembers how fucking works and starts to give it to you again. Terezi has pulled out, at least mostly, you think—that's the only reason you're still in one piece, probably—and it's still too much but it's back to being the hot kind of too much. 

You're trying to figure out whether you could manage liftoff under these revised launch conditions when Karkat starts shaking under you, little tremors at first like the—shit, do earthquakes have foreshocks? Is that a thing? Whatever, a geyser metaphor would have made more sense anyway, or maybe a volcano, something with hot jets of alien spooge and an excitingly ravaged countryside.

Which, wow, you're back in the danger zone for a second, your breath stuttering as you try not to freak out. "Here, I've got the bucket, get him up," Terezi says, and Karkat hauls you both up to kneeling despite what you're pretty sure must be grievous hazards to the integrity of his joints. The shift in position makes the weight of their collective deposits in the first galactic bank of dave bear down differently, and you can't decide if it feels better or worse but oh _god_ you want to be able to let go.

Terezi shoves the bucket between your thighs and reaches for your dick. You're still hard despite the excess—who are you kidding, _because of_ the excess—and you curse in ways so overwhelmed and mundane that they don't deserve to be committed to memory.

Karkat's teeth graze the rim of your ear and you shudder, arching your back—and that's when you realize he's pulling out, ever so gradually, the same slow undulating motion that got him up there in the first place. You sway between them, holding onto Terezi's shoulder and Karkat's hip like they could anchor you and keep you from completely falling apart, and it's good and you're a wreck and they've completely destroyed you just the way you love it and when Karkat's bulge finally slides all the way out of you, that's when you come, losing it at the awkward terrible perfect feeling of release as their come pours back out of you. Terezi strokes you through one aftershock after another, until you're twitching and oversensitive, until your thighs are drenched in technicolor troll nasty.

You slump, let your forehead fall against Terezi's shoulder. Karkat's claws run up and down your back, so light they almost tickle. They're both purring. You can tell the difference between their turned-on purrs and their _yeah, life is awesome_ purrs just by listening.

"So anyway, welcome back," you say when you can almost manage a nonchalant tone of voice.

Terezi snickers. "That was a first-rate celebration and I feel right at home."

"I'm purring on the inside," you say. Then you try to shift your weight, thinking maybe bathing ought to be next on the agenda, but no, you're not going anywhere just yet. You flop back onto Karkat instead of managing vertical motion. "Seriously, though, new rule, you guys aren't allowed to have any more weirdo bug growth spurts. You get that much bigger again and you'll kill me."

"Idiot," Karkat says into your hair. "We'll be as careful as your fragile mammal anatomy requires."

"Always," Terezi agrees.

"Oh." You listen to your heart beat. You think about everything buried under what they just said. You think about how tired and shaky and aching and _comfortable_ you feel right now. "Okay. That'll do."


End file.
